Alcohol use typically begins during adolescence in humans, with the age of initial use strongly predicting later alcohol abuse. Adolescents of a variety of species, including humans, differ neurobehaviorally from their adult counterparts; characteristic traits include an altered responsiveness to stressors as well as alterations in brain regions sensitive to activation by stressors and implicated in mediating the reinforcing effects of alcohol and other drugs of abuse. Yet, despite frequent alcohol use by adolescents and the implications of the early use for later abuse, study of alcohol and adolescence is still in its infancy. The work outlined in this proposal will use an animal model to examine the reinforcing efficacy of ethanol in adolescence, effects of stressors on this efficacy, and potential long-term consequences of adolescent exposure for later intake of ethanol. These issues will be examined using a model of adolescence in rats in which, during a compressed time period of around 2 weeks, developing rats exhibit certain characteristic neurobehavioral features of adolescence similar to those reported in adolescents of other species, including humans. Both males and females will be examined, due to reports of gender differences in ethanol responsiveness but the limited attention previously given this issue in animal studies with alcohol. Three specific aims are proposed: 1) to examine whether the reinforcing efficacy of ethanol is altered in adolescents relative to adults, and the role of chronic stress and corticosterone in contributing to age-related differences in ethanol reinforcement; 2) to establish whether alcohol intake in adolescence is more affected by stressors than such intake in adulthood; and 3) to determine whether prior exposure to ethanol and/or stress has a greater impact on subsequent ethanol consumption when that exposure occurs during adolescence than in adulthood. The results of this basic research should provide an essential initial base of data regarding ethanol reinforcement and stress during adolescence as well as potential long-lasting consequences of such exposure.